HIV infects humans and causes damage by taking over cells in the immune system—the part of the body that usually works to fight off germs, bacteria and disease. When that happens, the body may not be able to fight off certain types of illnesses or cancers. If the infection is not detected and treated, the immune system gradually weakens and AIDS develops. HIV and AIDS are terms that are often used together, and sometimes are used interchangeably, though they are not the same thing. If you are worried about a recent potential exposure, go to the emergency room and ask for PEP post-exposure prophylaxis as soon as you can.
Preventing Sexual Transmission of HIV
Oral Sex and HIV: What Are the Risks?
As the risk of transmission through oral sex is estimated to be much lower than for vaginal and anal intercourse in the absence of antiretroviral therapy, it is implausible that the risk of transmission through oral sex is not affected in the same way as other sexual transmission risks when effective treatment suppresses viral load. When HIV is not fully supressed, the risk of HIV transmission through the mouth is certainly smaller than through vaginal or anal intercourse. If undamaged, the tissues of the mouth and throat are thought to be less susceptible to infection than genital or anal tissues, and an enzyme in saliva also acts to inhibit HIV. Very few cases of transmission through oral sex have been reported amongst gay men despite the continued practice of oral sex often with ejaculation into the mouth by large numbers of men over many years. There are no reliable reports of HIV being transmitted from the mouth to the genitals. Cases of transmission via cunnilingus are extremely rare, and the reliability of these reports is questionable.
Oral Sex and HIV Risk
The chances of HIV being passed from one person to another depend on the type of contact. HIV is most easily spread or transmitted through unprotected anal sex, unprotected vaginal sex, and sharing injection drug equipment. Unprotected sex means sex in which no condoms or other barriers are used.
Back to Sexual health. HIV is transmitted through seminal and vaginal fluids, including menstrual fluids. The virus can enter the body through the bloodstream or by passing through delicate mucous membranes, such as inside the vagina, rectum or urethra. If a person gives fellatio and has bleeding gums, a cut, or an ulcer inside their mouth, HIV could enter their bloodstream through infected fluid.